Target Audience:
Sport ATV riders and recreational off-road enthusiasts
Market Segment:
Entry-to-mid level performance quad
Production Run:
14 model years, 1990 through 2003
Primary Competitors:
Honda TRX300X/400EX, Suzuki LT250R, Kawasaki Mojave
Key Advantage:
Proven air/oil-cooled 348cc engine with strong low-end torque and renowned Yamaha reliability
Longevity:
One of the longest-produced sport ATVs of its era with extensive aftermarket support
Engine:
348cc single-cylinder air/oil-cooled four-stroke
Transmission:
Six-speed manual clutch
Suspension:
Independent double wishbone front, swingarm rear
Brakes:
Dual front disc, single rear disc
Coverage Areas:
Complete vehicle: engine, drivetrain, chassis, suspension, brakes, electrical, fuel system
Manual Type:
Complete Workshop Service and Repair Manual
Delivery:
Instant digital download
Devices:
PC, Mac, tablets and smartphones
Printing:
Printable pages for workshop use
Requirements:
Any PDF reader
Engine Removal and Installation:
Step-by-step with torque specifications
Cylinder Head Service:
Valve inspection, clearance adjustment, resurfacing specs
Piston and Cylinder:
Measurement, wear limits, honing procedures
Crankshaft and Balancer:
Inspection, bearing service, assembly
Carburetor:
Disassembly, jetting, float height, tuning
Lubrication System:
Oil pump service, oil change procedures
Cooling:
Oil cooler lines and oil filter service
Clutch:
Disassembly, plate inspection, adjustment
Transmission:
Six-speed gearbox teardown, gear inspection, shift mechanism
Final Drive:
Chain service, sprocket wear limits
Front Suspension:
A-arm bushings, shock inspection and replacement
Rear Suspension:
Swingarm bearings, shock service
Steering:
Steering stem and tie-rod service
Wheels and Tires:
Specification tables
Front Brakes:
Caliper, pad, disc service with torque specs
Rear Brake:
Disc, caliper, master cylinder service
Ignition System:
CDI testing, stator, pickup coil specs
Electrical Components:
Wiring diagrams, switches, testing procedures
Starter System:
Starter motor and clutch overhaul
Frame and Body:
Fender removal, cable routing, bolt torque tables
Torque Specifications:
Full torque tables throughout all chapters
Troubleshooting:
Symptom-based diagnostic charts for engine, electrical, fuel and chassis
Wiring Diagrams:
Complete schematics for all covered years
Special Tools:
Tool numbers and substitutes where applicable
File Format:
PDF (searchable, bookmarked, zoomable)
Compatibility:
Windows, macOS, Linux, iOS, and Android — any device with a PDF reader
Requirements:
A PDF reader application (e.g. Adobe Acrobat Reader, free)
Searchability:
Fully text searchable for fast lookup of any topic
Print Quality:
High-resolution digital pages, printable at full clarity
Binding Type:
N/A — digital download, no physical binding
Paper Type:
N/A — digital download, no physical paper
Primary Engine:
348cc single-cylinder four-stroke
Engine Options Range:
Single engine option for all model years
Configuration:
Air/oil-cooled, SOHC, four-valve head
Bore and Stroke:
83 mm x 64.5 mm (approx. factory figures)
Compression Ratio:
Approximately 9.2:1
Carburetor:
Mikuni constant-velocity CV carburetor
Fuel System:
Carbureted, gravity-fed from under-seat fuel tank
Ignition:
CDI electronic ignition
Starting System:
Electric start with recoil backup
Lubrication:
Wet sump with oil cooler
Performance Figures:
N/A - factory did not publish standardized horsepower figures for this model
Standard Transmission:
Six-speed constant-mesh manual
Optional Transmission:
N/A - no automatic option offered on this model
Clutch:
Wet, multi-plate manual clutch with hand lever
Final Drive:
Chain drive to rear axle
Shifting:
Sequential foot-shift with shift pedal
Gearbox Service:
Full teardown and rebuild procedures covered in manual
Wheelbase:
Approximately 47.2 in (1,200 mm)
Overall Length:
Approximately 72.4 in (1,840 mm)
Overall Width:
Approximately 43.1 in (1,095 mm)
Ground Clearance:
Approximately 5.3 in (135 mm)
Curb Weight:
Approximately 397 lb (180 kg)
Fuel Capacity:
Approximately 2.4 US gal (9 L)
Front Brakes:
Dual hydraulic disc brakes
Rear Brake:
Single hydraulic disc brake
Lighting:
Headlight and taillight
Frame:
Steel tube backbone frame
Foot Protection:
Footpegs and heel guards
Crash Test Ratings:
N/A - ATVs are not subject to consumer crash test ratings
Operator Safety Note:
ATV use requires helmet and protective gear; not designed for passengers
Audio System:
N/A - off-road ATV, no audio equipment fitted
Driver Assistance Systems:
N/A - no electronic aids; rider-controlled machine
Ignition:
CDI electronic ignition with handlebar kill switch
Engine Oil:
Initial change after break-in, then every 1,000 km / 600 mi or 6 months
Oil Filter:
Replace with every other oil change
Air Filter:
Clean every ride in dusty conditions; inspect regularly
Valve Clearance:
Check and adjust periodically per schedule
Spark Plug:
Inspect and clean regularly, replace annually
Drive Chain:
Lubricate and adjust before every ride
Engine Oil Type:
SAE 10W-30 API SE or higher 4-stroke motorcycle oil
Oil Capacity:
Approximately 2.6 L with filter change
Final Gear / Chain Lube:
SAE 80-90 gear oil where fitted; chain lubricant for drive chain
Known Issues / Common Wear
Common Wear Items:
Chain, sprockets, brake pads, A-arm bushings, swingarm bearings
Known Issues:
Timing chain wear on high-mileage engines; carburetor gumming from stale fuel
Battery:
Check charge; replace every few seasons
Manufacturer:
Yamaha Motor Company, Japan
Manufacturer Heritage:
Yamaha built its reputation on motorcycles and powered products since 1955
Introduction:
Warrior 350 introduced in 1987 and continued with minor updates through 2003
Evolution:
Mechanically stable platform through the run, with mostly cosmetic and trim changes across 1990-2003
Successor:
Replaced in the Yamaha sport lineup by the Raptor 350
Production Location:
Yamaha plants in Japan
